Is there a way to suppress error message from probe command?

[Loving, Kent]

In grub.cfg, I'm using the probe command to detect the presence of a second 
drive. I need that info to set some parameters that are used later in the menu. 
This code works:

probe --set=junk -p (hd1)
proberet=$?
#is there a 2nd drive?
if [ $proberet == 0 ] ; then
# there are two or more
  ...
else
# only is only one
  ...
fi

Unfortunately, if there is only one drive, there is a flash of an error message 
"error: couldn't open device" just before the menu is displayed. Can that be 
suppressed?

Jordan Uggla said "There is an ugly hack that can be used to do this" in 
http://lists.gnu.org/archive/html/help-grub/2012-02/msg00020.html. I guess I 
would like to know what that hack is.

Kent Loving 
425-315-3043